src/xsmfns.c

   1 /* Session management module for systems which understand the X Session
   2    management protocol.
   3    Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008
   4      Free Software Foundation, Inc.
   5
   6 This file is part of GNU Emacs.
   7
   8 GNU Emacs is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GNU Emacs is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GNU Emacs; see the file COPYING.  If not, write to
  20 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21 Boston, MA 02110-1301, USA.  */
  22
  23 #include <config.h>
  24
  25 #ifdef HAVE_X_SM
  26
  27 #include <X11/SM/SMlib.h>
  28 #include <X11/Xlib.h>
  29 #include <X11/Xutil.h>
  30
  31 #ifdef HAVE_STRING_H
  32 #include <string.h>
  33 #else
  34 #ifdef HAVE_STRINGS_H
  35 #include <strings.h>
  36 #endif
  37 #endif
  38
  39 #ifdef HAVE_UNISTD_H
  40 #include <unistd.h>
  41 #endif
  42 #ifdef HAVE_STDLIB_H
  43 #include <stdlib.h>
  44 #endif
  45
  46 #include <sys/param.h>
  47 #include <stdio.h>
  48
  49 #include "lisp.h"
  50 #include "systime.h"
  51 #include "sysselect.h"
  52 #include "frame.h"
  53 #include "termhooks.h"
  54 #include "termopts.h"
  55 #include "xterm.h"
  56
  57 /* The user login name.  */
  58
  59 extern Lisp_Object Vuser_login_name;
  60
  61 /* This is the event used when SAVE_SESSION_EVENT occurs.  */
  62
  63 static struct input_event emacs_event;
  64
  65 /* The descriptor that we use to check for data from the session manager.  */
  66
  67 static int ice_fd = -1;
  68
  69 /* A flag that says if we are in shutdown interactions or not.  */
  70
  71 static int doing_interact = False;
  72
  73 /* The session manager object for the session manager connection.  */
  74
  75 static SmcConn smc_conn;
  76
  77 /* The client session id for this session.  */
  78
  79 static char *client_id;
  80
  81 /* The full path name to the Emacs program.  */
  82
  83 static char *emacs_program;
  84
  85 /* The client session id for this session as a lisp object.  */
  86
  87 Lisp_Object Vx_session_id;
  88
  89 /* The id we had the previous session.  This is only available if we
  90    have been started by the session manager with SMID_OPT.  */
  91
  92 Lisp_Object Vx_session_previous_id;
  93
  94 /* The option we tell the session manager to start Emacs with when
  95    restarting Emacs.  The client_id is appended.  */
  96
  97 #define SMID_OPT "--smid="
  98
  99
 100 /* The option to start Emacs without the splash screen when
 101    restarting Emacs.  */
 102
 103 #define NOSPLASH_OPT "--no-splash"
 104
 105
 106 /* Handle any messages from the session manager.  If no connection is
 107    open to a session manager, just return 0.
 108    Otherwise returns 1 if SAVE_SESSION_EVENT is stored in buffer BUFP.  */
 109
 110 int
 111 x_session_check_input (bufp)
 112      struct input_event *bufp;
 113 {
 114   SELECT_TYPE read_fds;
 115   EMACS_TIME tmout;
 116
 117   if (ice_fd == -1) return 0;
 118
 119   FD_ZERO (&read_fds);
 120   FD_SET (ice_fd, &read_fds);
 121
 122   tmout.tv_sec = 0;
 123   tmout.tv_usec = 0;
 124
 125   /* Reset this so wo can check kind after callbacks have been called by
 126      IceProcessMessages.  The smc_interact_CB sets the kind to
 127      SAVE_SESSION_EVENT, but we don't know beforehand if that callback
 128      will be called.  */
 129   emacs_event.kind = NO_EVENT;
 130
 131   if (select (ice_fd+1, &read_fds,
 132               (SELECT_TYPE *)0, (SELECT_TYPE *)0, &tmout) < 0)
 133     {
 134       ice_fd = -1;
 135       return 0;
 136     }
 137
 138
 139   if (FD_ISSET (ice_fd, &read_fds))
 140     IceProcessMessages (SmcGetIceConnection (smc_conn),
 141                         (IceReplyWaitInfo *)0, (Bool *)0);
 142
 143
 144   /* Check if smc_interact_CB was called and we shall generate a
 145      SAVE_SESSION_EVENT.  */
 146   if (emacs_event.kind == NO_EVENT)
 147     return 0;
 148
 149   bcopy (&emacs_event, bufp, sizeof (struct input_event));
 150   return 1;
 151 }
 152
 153 /* Return non-zero if we have a connection to a session manager.  */
 154
 155 int
 156 x_session_have_connection ()
 157 {
 158   return ice_fd != -1;
 159 }
 160
 161 /* This is called when the session manager says it is OK to interact with the
 162    user.  Here we set the kind to SAVE_SESSION_EVENT so an event is generated.
 163    Then lisp code can interact with the user.  */
 164
 165 static void
 166 smc_interact_CB (smcConn, clientData)
 167      SmcConn smcConn;
 168      SmPointer clientData;
 169 {
 170   doing_interact = True;
 171   emacs_event.kind = SAVE_SESSION_EVENT;
 172 }
 173
 174 /* This is called when the session manager tells us to save ourselves.
 175    We set the required properties so the session manager can restart us,
 176    plus the current working directory property (not mandatory) so we
 177    are started in the correct directory.
 178
 179    If this is a shutdown and we can request to interact with the user,
 180    we do so, because we don't know what the lisp code might do.  */
 181
 182 static void
 183 smc_save_yourself_CB (smcConn,
 184                       clientData,
 185                       saveType,
 186                       shutdown,
 187                       interactStyle,
 188                       fast)
 189      SmcConn smcConn;
 190      SmPointer clientData;
 191      int saveType;
 192      Bool shutdown;
 193      int interactStyle;
 194      Bool fast;
 195 {
 196 #define NR_PROPS 5
 197
 198   SmProp *props[NR_PROPS];
 199   SmProp prop_ptr[NR_PROPS];
 200
 201   SmPropValue values[20];
 202   int val_idx = 0;
 203   int props_idx = 0;
 204
 205   char *cwd = NULL;
 206   char *smid_opt;
 207
 208   /* How to start a new instance of Emacs.  */
 209   props[props_idx] = &prop_ptr[props_idx];
 210   props[props_idx]->name = SmCloneCommand;
 211   props[props_idx]->type = SmLISTofARRAY8;
 212   props[props_idx]->num_vals = 1;
 213   props[props_idx]->vals = &values[val_idx++];
 214   props[props_idx]->vals[0].length = strlen (emacs_program);
 215   props[props_idx]->vals[0].value = emacs_program;
 216   ++props_idx;
 217
 218   /* The name of the program.  */
 219   props[props_idx] = &prop_ptr[props_idx];
 220   props[props_idx]->name = SmProgram;
 221   props[props_idx]->type = SmARRAY8;
 222   props[props_idx]->num_vals = 1;
 223   props[props_idx]->vals = &values[val_idx++];
 224   props[props_idx]->vals[0].length = strlen (SDATA (Vinvocation_name));
 225   props[props_idx]->vals[0].value = SDATA (Vinvocation_name);
 226   ++props_idx;
 227
 228   /* How to restart Emacs (i.e.: /path/to/emacs --smid=xxxx --no-splash).  */
 229   props[props_idx] = &prop_ptr[props_idx];
 230   props[props_idx]->name = SmRestartCommand;
 231   props[props_idx]->type = SmLISTofARRAY8;
 232   props[props_idx]->num_vals = 3; /* /path/to/emacs, --smid=xxx --no-splash  */
 233   props[props_idx]->vals = &values[val_idx];
 234   props[props_idx]->vals[0].length = strlen (emacs_program);
 235   props[props_idx]->vals[0].value = emacs_program;
 236
 237   smid_opt = xmalloc (strlen (SMID_OPT) + strlen (client_id) + 1);
 238   strcpy (smid_opt, SMID_OPT);
 239   strcat (smid_opt, client_id);
 240
 241   props[props_idx]->vals[1].length = strlen (smid_opt);
 242   props[props_idx]->vals[1].value = smid_opt;
 243
 244   props[props_idx]->vals[2].length = strlen (NOSPLASH_OPT);
 245   props[props_idx]->vals[2].value = NOSPLASH_OPT;
 246   val_idx += 3;
 247   ++props_idx;
 248
 249   /* User id.  */
 250   props[props_idx] = &prop_ptr[props_idx];
 251   props[props_idx]->name = SmUserID;
 252   props[props_idx]->type = SmARRAY8;
 253   props[props_idx]->num_vals = 1;
 254   props[props_idx]->vals = &values[val_idx++];
 255   props[props_idx]->vals[0].length = strlen (SDATA (Vuser_login_name));
 256   props[props_idx]->vals[0].value = SDATA (Vuser_login_name);
 257   ++props_idx;
 258
 259   cwd = get_current_dir_name ();
 260
 261   if (cwd)
 262     {
 263       props[props_idx] = &prop_ptr[props_idx];
 264       props[props_idx]->name = SmCurrentDirectory;
 265       props[props_idx]->type = SmARRAY8;
 266       props[props_idx]->num_vals = 1;
 267       props[props_idx]->vals = &values[val_idx++];
 268       props[props_idx]->vals[0].length = strlen (cwd);
 269       props[props_idx]->vals[0].value = cwd;
 270       ++props_idx;
 271     }
 272
 273
 274   SmcSetProperties (smcConn, props_idx, props);
 275
 276   xfree (smid_opt);
 277
 278   if (cwd)
 279     free (cwd);
 280
 281   /* See if we maybe shall interact with the user.  */
 282   if (interactStyle != SmInteractStyleAny
 283       || ! shutdown
 284       || saveType == SmSaveLocal
 285       || ! SmcInteractRequest (smcConn, SmDialogNormal, smc_interact_CB, 0))
 286     {
 287       /* No interaction, we are done saving ourself.  */
 288       SmcSaveYourselfDone (smcConn, True);
 289     }
 290 }
 291
 292 /* According to the SM specification, this shall close the connection.  */
 293
 294 static void
 295 smc_die_CB (smcConn, clientData)
 296      SmcConn smcConn;
 297      SmPointer clientData;
 298 {
 299   SmcCloseConnection (smcConn, 0, 0);
 300   ice_fd = -1;
 301 }
 302
 303 /* We don't use the next two but they are mandatory, leave them empty.
 304    According to the SM specification, we should not interact with the
 305    user between smc_save_yourself_CB is called and until smc_save_complete_CB
 306    is called.  It seems like a lot of job to implement this and it doesn't
 307    even seem necessary.  */
 308
 309 static void
 310 smc_save_complete_CB (smcConn, clientData)
 311      SmcConn smcConn;
 312      SmPointer clientData;
 313 {
 314   /* Empty */
 315 }
 316
 317 static void
 318 smc_shutdown_cancelled_CB (smcConn, clientData)
 319      SmcConn smcConn;
 320      SmPointer clientData;
 321 {
 322   /* Empty */
 323 }
 324
 325 /* Error handlers for SM and ICE.  We don't want to exit Emacs just
 326    because there is some error in the session management.  */
 327
 328 static void
 329 smc_error_handler (smcConn,
 330                    swap,
 331                    offendingMinorOpcode,
 332                    offendingSequence,
 333                    errorClass,
 334                    severity,
 335                    values)
 336      SmcConn smcConn;
 337      Bool swap;
 338      int offendingMinorOpcode;
 339      unsigned long offendingSequence;
 340      int errorClass;
 341      int severity;
 342      SmPointer values;
 343 {
 344   /* Empty  */
 345 }
 346
 347 static void
 348 ice_error_handler (iceConn,
 349                    swap,
 350                    offendingMinorOpcode,
 351                    offendingSequence,
 352                    errorClass,
 353                    severity,
 354                    values)
 355      IceConn iceConn;
 356      Bool swap;
 357      int offendingMinorOpcode;
 358      unsigned long offendingSequence;
 359      int errorClass;
 360      int severity;
 361      IcePointer values;
 362 {
 363   /* Empty  */
 364 }
 365
 366
 367 static void
 368 ice_io_error_handler (iceConn)
 369      IceConn iceConn;
 370 {
 371   /* Connection probably gone.  */
 372   ice_fd = -1;
 373 }
 374
 375 /* This is called when the ICE connection is created or closed.  The SM library
 376    uses ICE as it transport protocol.  */
 377
 378 static void
 379 ice_conn_watch_CB (iceConn, clientData, opening, watchData)
 380      IceConn iceConn;
 381      IcePointer clientData;
 382      Bool opening;
 383      IcePointer *watchData;
 384 {
 385   if (! opening)
 386     {
 387       ice_fd = -1;
 388       return;
 389     }
 390
 391   ice_fd = IceConnectionNumber (iceConn);
 392 #ifndef F_SETOWN_BUG
 393 #ifdef F_SETOWN
 394 #ifdef F_SETOWN_SOCK_NEG
 395   /* stdin is a socket here */
 396   fcntl (ice_fd, F_SETOWN, -getpid ());
 397 #else /* ! defined (F_SETOWN_SOCK_NEG) */
 398   fcntl (ice_fd, F_SETOWN, getpid ());
 399 #endif /* ! defined (F_SETOWN_SOCK_NEG) */
 400 #endif /* ! defined (F_SETOWN) */
 401 #endif /* F_SETOWN_BUG */
 402
 403 #ifdef SIGIO
 404   if (interrupt_input)
 405     init_sigio (ice_fd);
 406 #endif /* ! defined (SIGIO) */
 407 }
 408
 409 /* Create the client leader window.  */
 410
 411 static void
 412 create_client_leader_window (dpyinfo, client_id)
 413      struct x_display_info *dpyinfo;
 414      char *client_id;
 415 {
 416   Window w;
 417   XClassHint class_hints;
 418   Atom sm_id;
 419
 420   w = XCreateSimpleWindow (dpyinfo->display,
 421                            dpyinfo->root_window,
 422                            -1, -1, 1, 1,
 423                            CopyFromParent, CopyFromParent, CopyFromParent);
 424
 425   class_hints.res_name = (char *) SDATA (Vx_resource_name);
 426   class_hints.res_class = (char *) SDATA (Vx_resource_class);
 427   XSetClassHint (dpyinfo->display, w, &class_hints);
 428   XStoreName (dpyinfo->display, w, class_hints.res_name);
 429
 430   sm_id = XInternAtom (dpyinfo->display, "SM_CLIENT_ID", False);
 431   XChangeProperty (dpyinfo->display, w, sm_id, XA_STRING, 8, PropModeReplace,
 432                    client_id, strlen (client_id));
 433
 434   dpyinfo->client_leader_window = w;
 435 }
 436
 437 /* Try to open a connection to the session manager.  */
 438
 439 void
 440 x_session_initialize (dpyinfo)
 441      struct x_display_info *dpyinfo;
 442 {
 443 #define SM_ERRORSTRING_LEN 512
 444   char errorstring[SM_ERRORSTRING_LEN];
 445   char* previous_id = NULL;
 446   SmcCallbacks callbacks;
 447   int  name_len = 0;
 448
 449   /* Check if we where started by the session manager.  If so, we will
 450      have a previous id.  */
 451   if (! EQ (Vx_session_previous_id, Qnil) && STRINGP (Vx_session_previous_id))
 452     previous_id = SDATA (Vx_session_previous_id);
 453
 454   /* Construct the path to the Emacs program.  */
 455   if (! EQ (Vinvocation_directory, Qnil))
 456     name_len += strlen (SDATA (Vinvocation_directory));
 457   name_len += strlen (SDATA (Vinvocation_name));
 458
 459   /* This malloc will not be freed, but it is only done once, and hopefully
 460      not very large   */
 461   emacs_program = xmalloc (name_len + 1);
 462   emacs_program[0] = '\0';
 463
 464   if (! EQ (Vinvocation_directory, Qnil))
 465     strcpy (emacs_program, SDATA (Vinvocation_directory));
 466   strcat (emacs_program, SDATA (Vinvocation_name));
 467
 468   /* The SM protocol says all callbacks are mandatory, so set up all
 469      here and in the mask passed to SmcOpenConnection.  */
 470   callbacks.save_yourself.callback = smc_save_yourself_CB;
 471   callbacks.save_yourself.client_data = 0;
 472   callbacks.die.callback = smc_die_CB;
 473   callbacks.die.client_data = 0;
 474   callbacks.save_complete.callback = smc_save_complete_CB;
 475   callbacks.save_complete.client_data = 0;
 476   callbacks.shutdown_cancelled.callback = smc_shutdown_cancelled_CB;
 477   callbacks.shutdown_cancelled.client_data = 0;
 478
 479   /* Set error handlers.  */
 480   SmcSetErrorHandler (smc_error_handler);
 481   IceSetErrorHandler (ice_error_handler);
 482   IceSetIOErrorHandler (ice_io_error_handler);
 483
 484   /* Install callback for when connection status changes.  */
 485   IceAddConnectionWatch (ice_conn_watch_CB, 0);
 486
 487   /* Open the connection to the session manager.  A failure is not
 488      critical, it usually means that no session manager is running.
 489      The errorstring is here for debugging.  */
 490   smc_conn = SmcOpenConnection (NULL, NULL, 1, 0,
 491                                 (SmcSaveYourselfProcMask|
 492                                  SmcDieProcMask|
 493                                  SmcSaveCompleteProcMask|
 494                                  SmcShutdownCancelledProcMask),
 495                                 &callbacks,
 496                                 previous_id,
 497                                 &client_id,
 498                                 SM_ERRORSTRING_LEN,
 499                                 errorstring);
 500
 501   if (smc_conn != 0)
 502     {
 503       Vx_session_id = make_string (client_id, strlen (client_id));
 504
 505 #ifdef USE_GTK
 506       /* GTK creats a leader window by itself, but we need to tell
 507          it about our client_id.  */
 508       gdk_set_sm_client_id (client_id);
 509 #else
 510       create_client_leader_window (dpyinfo, client_id);
 511 #endif
 512     }
 513 }
 514
 515 /* Ensure that the session manager is not contacted again. */
 516
 517 void
 518 x_session_close ()
 519 {
 520   ice_fd = -1;
 521 }
 522
 523
 524 DEFUN ("handle-save-session", Fhandle_save_session,
 525        Shandle_save_session, 1, 1, "e",
 526        doc: /* Handle the save_yourself event from a session manager.
 527 A session manager can tell Emacs that the window system is shutting down
 528 by sending Emacs a save_yourself message.  Emacs executes this function when
 529 such an event occurs.  This function then executes `emacs-session-save'.
 530 After that, this function informs the session manager that it can continue
 531 or abort shutting down the window system depending on the return value
 532 from `emacs-session-save'  If the return value is non-nil the session manager
 533 is told to abort the window system shutdown.
 534
 535 Do not call this function yourself. */)
 536      (event)
 537      Lisp_Object event;
 538 {
 539   /* Check doing_interact so that we don't do anything if someone called
 540      this at the wrong time. */
 541   if (doing_interact)
 542     {
 543       Bool cancel_shutdown = False;
 544
 545       cancel_shutdown = ! EQ (call0 (intern ("emacs-session-save")), Qnil);
 546
 547       SmcInteractDone (smc_conn, cancel_shutdown);
 548       SmcSaveYourselfDone (smc_conn, True);
 549
 550       doing_interact = False;
 551     }
 552
 553   return Qnil;
 554 }
 555
 556 \f
 557 /***********************************************************************
 558                             Initialization
 559  ***********************************************************************/
 560 void
 561 syms_of_xsmfns ()
 562 {
 563   DEFVAR_LISP ("x-session-id", &Vx_session_id,
 564     doc: /* The session id Emacs got from the session manager for this session.
 565 Changing the value does not change the session id used by Emacs.
 566 The value is nil if no session manager is running.
 567 See also `x-session-previous-id', `emacs-save-session-functions',
 568 `emacs-session-save' and `emacs-session-restore'." */);
 569   Vx_session_id = Qnil;
 570
 571   DEFVAR_LISP ("x-session-previous-id", &Vx_session_previous_id,
 572     doc: /* The previous session id Emacs got from session manager.
 573 If Emacs is running on a window system that has a session manager, the
 574 session manager gives Emacs a session id.  It is feasible for Emacs Lisp
 575 code to use the session id to save configuration in, for example, a file
 576 with a file name based on the session id.  If Emacs is running when the
 577 window system is shut down, the session manager remembers that Emacs was
 578 running and saves the session id Emacs had.
 579
 580 When the window system is started again, the session manager restarts
 581 Emacs and hands Emacs the session id it had the last time it was
 582 running.  This is now the previous session id and the value of this
 583 variable.  If configuration was saved in a file as stated above, the
 584 previous session id shall be used to reconstruct the file name.
 585
 586 The session id Emacs has while it is running is in the variable
 587 `x-session-id'.  The value of this variable and `x-session-id' may be the
 588 same, depending on how the session manager works.
 589
 590 See also `emacs-save-session-functions', `emacs-session-save' and
 591 `emacs-session-restore'." */);
 592   Vx_session_previous_id = Qnil;
 593
 594   defsubr (&Shandle_save_session);
 595 }
 596
 597 #endif /* HAVE_X_SM */
 598
 599 /* arch-tag: 56a2c58c-adfa-430a-b772-130abd29fd2e
 600    (do not change this comment) */